This is what my dataframe looks like, How can i fetch column b of the dataframe where a=[98,43,23,2,5] such that it returns [12,39,23,32,78]
a b c
2 32 34
5 78 23
98 12 11
23 23 66
43 39 43
I want to write a method that takes in a list(to compare with column a), and returns a list back(corresponding values of b) from the dataframe.
def get_reordered_b_according_to_a(a_list):
#code
return reordered_list_b
How can I do this efficiently?
Use DataFrame.set_index with DataFrame.reindex, if some value ixist in list and not in column a is returned NaNs:
a=[98,43,23,2,5]
def get_reordered_b_according_to_a(a_list):
return df.set_index('a').b.reindex(a_list).tolist()
print (get_reordered_b_according_to_a(a))
[12, 39, 23, 32, 78]
a=[43,23,2,5,7]
def get_reordered_b_according_to_a(a_list):
return df.set_index('a').b.reindex(a_list).tolist()
print (get_reordered_b_according_to_a(a))
[39.0, 23.0, 32.0, 78.0, nan]
